Hamming Distance is a measure of how different two strings of equal length are. It counts the number of positions at which the corresponding symbols differ. For example, the Hamming distance between the strings "karolin" and "kathrin" is 3, as they differ in three positions. This concept is widely used in computer science, particularly in error detection and correction. By calculating the Hamming distance, systems can identify and correct errors in data transmission, ensuring that the information received is accurate and reliable.